Impact of a 16-week strength training program on physical performance, body composition and cardiac remodeling in previously untrained women and men

Abstract

Even if more and more women are involved in strength-training (ST) programs in fitness centers, studies on strength gain, body composition, and cardiac remodeling were mainly conducted in men and whether they are similar in women remains to be explored. In this context, the aim of our study was to assess the effect of a supervised ST program on strength gains, body composition, and cardiac remodeling in previously untrained women and men. 17 healthy and previously untrained young women and 17 young men participated in a supervised 16-week ST program built according to the recommendation of the American College of Sports Medicine in terms of intensity, and strictly using similar volume and intensity in both groups. Strength performance, body composition, and cardiac remodeling were evaluated every 4 weeks. Cardiac adaptations were assessed using resting echocardiography, including regional 2D-Strain analysis of the left atrium and ventricle (LA and LV, respectively). Despite lower values at baseline, women exhibited similar or even higher strength gains compared to men. ST induced a decrease of body and abdominal fat mass and an increase of lean body mass in both groups. Similar cardiac remodeling was observed in women, and women, including an early and progressive LV and LA enlargement throughout the ST program, without any alteration of LV diastolic and systolic functions. These findings underlie that ST programs are highly suitable for women to enhance their strength performance and their cardiovascular health.

Keywords: body composition; cardiovascular health; strength‐training; women.

FIGURE 1

Flow chart of patient recruitment with inclusion and exclusion criteria consideration.

FIGURE 2

Alterations of strength performance and body composition during the 16‐week of strength‐training program including (A) 1‐RM for the bench press, (B) 1‐RM for the squat, (C) lean body mass, (D) percentage of body fat and (E) abdominal fat mass. On the right‐side, histograms represent the percentage of change from baseline in both groups with effect size (number above histogram represents Cohen's d with [confidence intervals], blue: small effect, green: moderate effect, yellow: large effect and orange: very large effect). *, significantly different from other evaluation (*, p < 0.05; **, p < 0.01; ***, p < 0.001); ##, significant differences between groups at baseline (p < 0.01).

FIGURE 3

Alteration of left ventricular morphological parameters over the 16‐week strength‐training program. (A) Left ventricular interventricular septum thickness (IVST), (B) Left ventricular end‐diastolic volume indexed to body surface area, (C) Left ventricular mass indexed to body surface area (LVMi) and (D) relative wall thickness (RWT). On the right‐side, histograms represent the percentage of change from baseline in both groups with effect size (number above histogram represents Cohen's d with [confidence intervals], blue: small effect, green: moderate effect, yellow: large effect and orange: very large effect). *, significantly different from other evaluations (*, p < 0.05; **, p < 0.01; ***, p < 0.001); ##, group differences (p < 0.01).

FIGURE 4

Alterations of left ventricular function over the 16‐week strength‐training program. (A) transmitral Doppler E wave, (B) transmitral Doppler A wave, (C) Tissue Doppler E′ mean on the septum and lateral wall, (D) ejection fraction (EF) and (E) global longitudinal strain (GLS). On the right‐side, histograms represent the percentage of change from baseline in both groups with effect size (number above histogram represents Cohen's d with [confidence intervals], blue: small effect, green: moderate effect). *, significantly different from other evaluations (*, p < 0.05; **, p < 0.01); #, significant group differences (#, p < 0.05; ##, p < 0.01).

FIGURE 5

Alteration of left atrial morphology and function over the 16‐week strength‐training program. (A) Left atrium volume index (LAVI), (B) reservoir function, (C) conduct function and (D) booster pump. On the right‐side, histograms represent the percentage of change from baseline in both groups with effect size (number above histogram represents Cohen's d with [confidence intervals], blue: small effect). **, significantly different from other evaluations (**, p < 0.01); #, significant group differences (p < 0.05).